Since 2004, researchers in NOAA’s Global Monitoring Division have released the Annual Greenhouse Gas Index: a single value that compares the total warming effect of each year's concentrations of heat-trapping gases to 1990 levels.

According to the 2009 National Climate Assessment, heavy downpours have increased in frequency and intensity during the last 50 years. Models predict that downpours will become still more more frequent and intense as greenhouse gas emissions and the planet’s temperature continue to rise.

Despite the double-dip La Nina that occurred throughout the year, 2011 was still among the 15 warmest years on record. Including the 2011 temperature, the rate of warming since 1971 is now between 0.14° and 0.17° Celsius per decade (0.25°-0.31° Fahrenheit), and 0.71-0.77° Celsius per century (1.28°-1.39° F) since 1901.

It is virtually certain our world will continue to warm over this century and beyond. The exact amount of warming that will occur in the coming century depends largely on the energy choices that we make now and in the next few decades.

Humans currently release about 70 million tons of carbon dioxide every day into the atmosphere and about 20 million tons is being absorbed regularly by the oceans, causing the pH to drop. Chris Sabine describes current and projected future impacts of this acidification on marine ecology.

Molly Heller is part of a team of scientists who processes flasks of air samples in NOAA’s Earth System Research Laboratory in Boulder, CO. Week in and week out, Heller and her colleagues unpack sealed glass flasks shipped back to Boulder from dozens of remote sites around the world. What’s inside is priceless: air captured from a site near Tasmania’s Cape Grim; from Summit, Greenland; the Canary Islands; the South Pole.

The types of tree species that grow in a particular region determine the range of bright colors that paint our landscapes during the fall season. In the future, scientists project that the forest habitats all around us may undergo major changes to due to warming temperatures.